Title of Oral/Poster Presentation

Effects of Shigella flexneri Infection on Major Vault Protein Expression and Localization in HeLa Cells

Presenter Information

Jenna HawleyFollow

Class

Article

Department

Chemistry and Biochemistry

Faculty Mentor

Nicholas Dickenson

Presentation Type

Poster Presentation

Abstract

At 13 MDa, vault proteins are the largest known ribonucleoprotein particles to date. They are found in nearly all eukaryotic cells, though their function(s) remains unclear. Vaults are comprised of multiple copies of three proteins and four short untranslated RNAs. 70% of the vault complex's mass comes from the major vault protein (MVP), a 97 kDa protein has been speculated to play a role in supporting the immune response against bacterial infections. Here, we developed a series of assays to investigate the effects of S. flexneri exposure on MVP expression levels and distribution within cultured HeLa cells. Specifically, the sectioning capabilities of a laser scanning confocal microscope probed sub-cellular MVP localization in HeLa cells that were exposed to a control solution or several strains of Shigella prior to immunofluorescent labeling of MVP. Initial studies suggested that exposure to virulent, invasive strains of S. flexneri may have resulted in an increase in MVP expression levels and a shift in subcellular localization of MVP within HeLa cells as compared to controls. Follow-up studies suggest, however, that MVP levels and distribution are not in fact altered and that vaults are not likely involved in host responses to Shigella exposure as has been seen for some other infections, indicating that vault response to bacterial exposure is not universal and that it requires additional follow-up studies to determine their potential role in immune response.

Start Date

4-9-2015 1:30 PM

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Apr 9th, 1:30 PM

Effects of Shigella flexneri Infection on Major Vault Protein Expression and Localization in HeLa Cells

At 13 MDa, vault proteins are the largest known ribonucleoprotein particles to date. They are found in nearly all eukaryotic cells, though their function(s) remains unclear. Vaults are comprised of multiple copies of three proteins and four short untranslated RNAs. 70% of the vault complex's mass comes from the major vault protein (MVP), a 97 kDa protein has been speculated to play a role in supporting the immune response against bacterial infections. Here, we developed a series of assays to investigate the effects of S. flexneri exposure on MVP expression levels and distribution within cultured HeLa cells. Specifically, the sectioning capabilities of a laser scanning confocal microscope probed sub-cellular MVP localization in HeLa cells that were exposed to a control solution or several strains of Shigella prior to immunofluorescent labeling of MVP. Initial studies suggested that exposure to virulent, invasive strains of S. flexneri may have resulted in an increase in MVP expression levels and a shift in subcellular localization of MVP within HeLa cells as compared to controls. Follow-up studies suggest, however, that MVP levels and distribution are not in fact altered and that vaults are not likely involved in host responses to Shigella exposure as has been seen for some other infections, indicating that vault response to bacterial exposure is not universal and that it requires additional follow-up studies to determine their potential role in immune response.